SMD vs COB vs GOB vs Mini LED vs Micro LED
The complete guide to LED packaging technologies and how to choose.
Five distinct LED packaging technologies compete in the display market today. SMD (Surface Mount Device) has dominated for a decade, but COB (Chip-on-Board), GOB (Glue-on-Board), Mini LED, and Micro LED are rapidly reshaping the industry. This guide explains each technology's construction, advantages, limitations, and ideal applications.
Key Facts at a Glance
- Market dominant
- SMD — 70%+ of all commercial LED displays
- Fastest growing
- COB — for fine pitch indoor applications
- Ultra-fine pitch future
- Micro LED — below P0.5
- Durability leader
- GOB (Glue-on-Board) — IP-protected for challenging environments
SMD (Surface Mount Device)
SMD is the most widely used LED packaging in commercial displays today. Individual red, green, and blue LED chips are mounted inside a tiny plastic package (approximately 1.5 × 1.5 mm for indoor SMD) and soldered directly to the PCB circuit board. Each SMD package contains three separate chips (R, G, B) that combine to produce any colour in the visible spectrum. SMD displays are cost-effective, well-understood, and available across the full pixel pitch range from P1.2 to P20.
| Specification | SMD Detail |
|---|---|
| Package size | 0.5 mm × 0.5 mm (SMD0505) to 3.5 mm × 3.5 mm (SMD3535) |
| Pixel pitch range | P1.0 to P20 |
| Brightness | 800 – 10,000 nits (application-dependent) |
| Viewing angle | 140° – 160° horizontal |
| Repairability | Individual pixel replacement possible |
| Cost | Low to medium |
| Best for | General indoor and outdoor commercial displays |
COB (Chip-on-Board)
COB technology bonds LED chips directly onto the PCB substrate, then encapsulates them under a single uniform layer of phosphor epoxy. There are no individual plastic packages — the result is a smooth, flat surface with no exposed discrete components. COB displays offer superior contrast (the dark epoxy creates deeper blacks between pixels), better uniformity, greater mechanical durability (no protruding packages to break), and superior moisture resistance. COB is the technology of choice for ultra-fine pitch (P0.9 – P2.0) indoor applications.
COB displays cannot have individual pixels replaced if damaged. A full module replacement is required. This makes professional installation and careful handling critical — but also means COB modules have far fewer failure points than SMD in day-to-day operation.
GOB (Glue-on-Board)
GOB is SMD technology with an additional protective epoxy coating applied over the entire module surface. This glue layer protects individual SMD packages from physical damage, moisture, dust, and accidental impacts. GOB displays are rated IP54 on the front surface, making them suitable for semi-outdoor, hospitality, and high-traffic environments where standard SMD would be vulnerable. The glue layer slightly reduces brightness and can affect colour consistency if not applied by a reputable manufacturer.
Mini LED
Mini LED refers to LED chips in the 100–200 micron range — smaller than standard SMD but larger than Micro LED. Mini LED is primarily used as a backlight technology for high-end LCD displays (rather than as a self-emissive pixel technology) enabling local dimming zones that dramatically improve contrast. In the direct-view LED display market, Mini LED enables pixel pitches below P1.0 at lower cost than full Micro LED. Products are available from P0.7 to P1.5.
Micro LED
Micro LED is the next generation of display technology — individual LED chips are below 50 microns (0.05 mm) and are transfer-printed onto a substrate at extremely high density. Micro LED delivers self-emissive pixels with infinite contrast (true black by turning pixels completely off), peak brightness exceeding 10,000 nits, and lifespans projected at 100,000+ hours. Current challenges: extremely high cost, complex manufacturing, and difficulty achieving economically viable yield rates at scale. Micro LED is currently deployed in premium consumer displays and specialist command center applications.
| Technology | Pixel Pitch | Durability | Cost | Repairability | Best For |
|---|---|---|---|---|---|
| SMD | P1.0 – P20 | Good | Low–Medium | Individual pixel | General commercial |
| COB | P0.9 – P2.0 | Excellent | Medium–High | Module only | Fine pitch indoor, boardrooms |
| GOB | P1.5 – P6 | Excellent (IP54) | Medium | Module only | Semi-outdoor, hospitality |
| Mini LED | P0.7 – P1.5 | Good | High | Module only | Studio, premium retail |
| Micro LED | P0.1 – P0.5 | Excellent | Very High | Specialist | Command centers, premium |
Frequently Asked Questions
Should I choose SMD or COB for a boardroom display?
For P1.5 – P2.0 boardroom displays, COB is recommended. It delivers better uniformity, deeper blacks, and greater durability without individual package failure risks. For P2.5 and above, SMD is cost-effective and reliable.
Is GOB necessary for outdoor displays?
Standard outdoor LED uses SMD3535 packages which are inherently more robust than indoor SMD. GOB is not typically necessary for fully outdoor IP65-rated displays, but is valuable for semi-outdoor environments.
When will Micro LED replace SMD?
Mass-market Micro LED at competitive price points is projected for 2027–2030. For most commercial applications, COB and high-quality SMD will remain the optimal choice through this decade.
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